A jury at the Provincial Court in Girona, north east Spain, found her guilty of murder charges after deciding she was criminally responsible for the children's deaths.

Smith was seeking an acquittal, claiming she was in a state of "psychiatric disturbance" and suffering insurmountable fear when the tragedy happened.

But the jury rejected her claim that she was "totally disturbed" or she was so scared she could not be expected to act in any other way when she committed the murders.

Wearing a dark top, black trousers and flip flops, Smith remained calm when the verdict was read out. After the verdict was given, Victor Pillado Quintas, for the prosecution, asked for her to be jailed for a total of 34 years.

Judge Adolfo Garcia Morales is now expected to release a written sentence in the coming weeks. Rejecting Smith's claim that she was in a psychotic state when she murdered her children, the jury foreman said: "The defendant admitted during the trial that she was fully conscious of what she was doing and knew it was wrong."

During his closing remarks, Mr Pillado Quintas described the killings as "horrid, vile and despicable". Speaking outside the courthouse after the verdict, he said: "Justice has been done, these were abominable crimes."

The murders took place shortly after Smith's partner, Martin Smith, was arrested in Barcelona by Spanish police acting on a European arrest warrant. The family had been living in Spain since 2007 after fleeing Lichfield, Staffordshire, because Smith's eldest daughter by her first husband accused Mr Smith of raping her.

In December 2010, Martin Smith was found guilty at Manchester Crown Court of using hypnosis, bullying and violence to groom and sexually abuse Sarah Richardson, who has waived her right to anonymity. Last January, the 46-year-old was found hanged in his cell at Strangeways Prison in Manchester.